Advanced Higher Chemistry grade boundaries 2025: marks for A, B, C and D

Advanced Higher Chemistry grade boundaries 2025

The numbers below come from the SQA Grade boundaries 2025 workbook. The 2025 course report for Advanced Higher Chemistry prints the same minimum mark for each grade.

The total of 160 covers the question paper, which has a multiple-choice Section 1 and an extended-response Section 2, and the project, a written investigation. The grade comes from all of it added together. Use the data booklet guide to see what the exam gives you and the Advanced Higher Chemistry guide for the course content.

From marks to a grade: 99 out of 160

Suppose a candidate's paper and project together come to 99. The B boundary is 92 and the A boundary is 108, so 99 is a B. It is 7 marks above the B line and 9 marks short of an A. Dropping to 91 would turn the B into a C.

Only C, A and upper A are chosen by hand. With C at 76 and A at 108, the gap is 32, and the rest follow: B = 76 + ⌊(2 × 32 + 1) ÷ 4⌋ = 92 and D = 76 − ⌈(2 × 32 − 1) ÷ 4⌉ = 60.

How 2025 compares with 2024

A 4-mark rise at A, B, C and D, and 1 mark at upper A, is a bigger move than Physics or Computing Science made that year, and it sits oddly with the course report, which says Section 2, the extended-response section, was more demanding than anticipated and that the boundaries were adjusted to account for it. Section 1 performed as expected, with performance slightly higher than the year before. What the published numbers show is that a 2025 candidate needed 76 for a C where a 2024 candidate needed 72.

Advanced Higher Chemistry boundaries since 2019

The maximum was 130 in 2019, 120 in 2022 and 2023, and 160 from 2024, so work in percentages. The A boundary was 68% in 2025 and 65% in 2024, and the C boundary 48% against 45%.

Entries and results

The report counts 2,767 resulted entries in 2025, against 2,746 in 2024, before the appeals process was complete.

Exactly 30.0% of the entry got an A, the highest A rate among the three Advanced Higher sciences that year, and 9.0% got No Award.

Where candidates lost marks in 2025

• Optical isomers. In 1(c) few said that the isomers rotate plane-polarised light by an equal amount in opposite directions, though most gave the opposite directions.
• Indicators. In 2(c)(i) many explained where the colour of one form came from and not what brings about the colour change when pH alters.
• Gravimetric analysis. In 3(c) few gained both marks for chloride in g per litre, and some did not write the formula for silver(I) chloride.
• Isomer mixtures. In 4(b)(ii) many listed addition reactions without showing how they lead to isomers or how the isomers are separated.
• Solvent extraction. In 5(d)(i) many described the wrong practical technique.
• Project. Performance was higher than last year: most candidates wrote a clear abstract, chose an appropriate level of complexity, duplicated their procedures and compared results with literature values.

Using today's paper with these lines

Today's Advanced Higher Chemistry paper is a short timed paper of 8 questions worth 25 to 35 marks. Mark it with the worked answers that come once it is marked, work out your percentage and compare it with 68% for the A line and 48% for the C line. It has no project, so a high score does not account for the project marks in your real total.

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Scotland · Advanced HigherAdvanced Higher Chemistry grade boundaries 2026Qualifications Scotland's 2026 Advanced Higher Chemistry boundaries out of 160: A at 108, C at 73. See the fall from 2025 and what each mark earned.